NT
Bahia Antwren Herpsilochmus pileatus



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2023 Near Threatened C1+2a(i)
2016 Vulnerable B1ab(i,ii,iii,v);C2a(i)
2012 Vulnerable B1ab(i,ii,iii,v);C2a(i)
2008 Vulnerable B1a+b(i,ii,iii); C2a(i)
2004 Vulnerable
2002 Vulnerable
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status not a migrant Forest dependency does not normally occur in forest
Land-mass type continent
Average mass -
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 43,800 km2 medium
Area of Occupancy (breeding/resident) 9,680 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 4200-13000 mature individuals poor inferred 2023
Population trend decreasing poor suspected 2017-2027
Rate of change over the past 10 years/3 generations (longer of the two periods) 10-19% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 10-19% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 10-19% - - -
Generation length 2.57 years - - -
Number of subpopulations 10-100 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The population size has not been quantified, but the species is described as locally common (Zimmer et al. 2020). Assuming that the species occurs at the same density as two congeners (H. stictocephalus and H. sticturus: 2-5 mature individuals/km2; Santini et al. 2018), and assuming that 50% of forests within the range are occupied (i.e., 2,100-2,600 km2; Global Forest Watch 2022), the population may number 4,200-13,000 mature individuals.

Trend justification: There are no data on the population trend, but due to the species' specific habitat requirements declines are suspected on the basis of ongoing forest loss and degradation.
Over ten years, 9% of tree cover is lost within the range (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). As the species has limited dispersal abilities and is confined to small, isolated subpopulations in disjunct patches of restinga forest (ICMBio 2018), population declines may be steeper than the rate of tree cover loss suggests due to increasing fragmentation between occupied patches. Tentatively, population declines are here placed in the band 10-19% over ten years.


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Brazil extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Brazil Estação Veracruz
Brazil Foz dos Rios Pardo e Jequitinhonha and Santa Cruz Cabrália / Belmonte
Brazil Ilhéus / Itabuna
Brazil Parque Nacional do Pau Brasil / Trancoso

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Savanna Dry major resident
Altitude 0 - 840 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Livestock farming & ranching - Agro-industry grazing, ranching or farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2024) Species factsheet: Bahia Antwren Herpsilochmus pileatus. Downloaded from https://datazone.birdlife.org/species/factsheet/bahia-antwren-herpsilochmus-pileatus on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.